The CW's upcoming DC's Legends of Tomorrow will assemble a motley crew of superheroes and villains that've previously appeared on Arrow and/or The Flash on a time-travel adventure to prevent the immortal Vandal Savage (Casper Crump) from taking over the world in the future. Series creators Greg Berlanti, Marc Guggenheim, and Andrew Kreisberg have designed Legends of Tomorrow to have an anthology narrative structure; as such, season 1 will feature a largely self-contained storyline, even as it continues to expand the CW's DC TV show universe and introduce more characters into the mix.
So far, the known list of new additions who will appear on Legends of Tomorrow season 1 includes a new love interest for White Canary (Caity Lotz) and a robotics experts portrayed by fan-favorite Firefly alum Jewel Straite. There will be a number of familiar faces who pop up for an episode or two as well; including, older versions of two well-known superheroes. Moreover, we now have confirmation that the Legends will cross paths with one particularly well-known DC Comics characters who's never appeared in the Arrow/Flash-verse before: Jonah Hex.
Guggenheim revealed the news during an interview with Variety, where he explained that Jonah Hex will appear in a Legends of Tomorrow episode that takes the Legends back to the Old West (see his quote below). However, for the time being, the identity of the actor who will bring Hex to life on the CW TV show remains under-wraps.
“Ever since we decided that ‘Legends’ would involve time travel, we were eager to do a story set in the Old West. But if you’re going to do a story set in the DC Universe version of the Old West, you simply MUST include Jonah Hex in it. We’re thrilled about bringing another well known, beloved DC character to television.”
Jonah Hex, for those unfamiliar, is a hard-edged and heavily-scarred former Confederate soldier-turned bounty from the Old West in the DC Comics. Hex made appearances on such DC cartoon TV shows as Justice League and Batman: The Brave and the Bold, prior to his live-action appearance with the 2010 Jonah Hex movie (starring Josh Brolin as its namesake) - itself, an unabashed critical and commercial flop alike. Hence, there's really no where for the Hex character to go but up when it comes to his live-action iteration on Legends of Tomorrow (regardless of who plays him).
Keep in mind: while Jonah Hex appearing on Legends of Tomorrow means that he will officially become part of The CW's shared DC TV show continuity as a result, that doesn't mean he'll become more than a (hopefully fun) one-off guest star. Case in point: Matt Ryan's John Constantine showed up during an episode of Arrow season 4 back in 2015, but for the time being it remains unclear if the character will ever show up on Arrow again or another CW/DC series in the future - much less, have his own TV show resurrected. Hex will probably be in the same boat, after Legends of Tomorrow season 1 is done.
Then again, who knows - The CW is clearly looking to keep its DC TV show universe going after Arrow and The Flash are both done, between the creation of Legends of Tomorrow and the way the network is keeping its options open regarding potential future superhero TV shows (like, for example, a Vixen live-action series). A Jonah Hex TV show would be a different sort of genre series altogether than anything else currently airing on The CW, so there's room for one to flourish - though that possibility depends on how viewers take to Jonah Hex on Legends of Tomorrow in the first place, of course.
The Flash will return on Tuesday, January 19, 2016, while Arrow will return on Wednesday, January 20, 2016 and Legends of Tomorrow will see its series premiere on Thursday, January 21, 2016.